15 to 0. The size of the cation increases as we move from Li+ to Rb+. and in general, if you have a lot of charge you come out in front. conductivity is defined as the conducting power of all the ions produced by dissolving one mole of an electrolyte in solution. Example Definitions Formulaes. Solved Examples on Conductance of Electrolytic Solutions. The influence of ion-ion interactions on the conductivity of strong electrolytes was studied by Debye and Huckel. Molar Conductance:-The Conductivity of an Electrolyte divided by the Molar concentratIon is said to be the Molar Conductance. (a, b) 2. λ = kM. (iv) Copper will deposit at anode. of the solution , so specific conductivity decrease with dilution Molar conductance and Equivalent conductance is the product of specific conductivity and volume. Conductivity κ , is equal to _____. This experiment was conducted at four. 1 mol L-1 solution of NaCl is 1. To clarify the regularity of the appearance of the maximum on the κ− c curves, let us consider how the distance between ions in. (iii) concentration of electrolytes in solution. At. Concentration of electrolytes in solution d. Thus. S. So, the correct order of increasing ionic conductance is as follows: Li+ < N a+ < K+ < Rb+. When you dissolve one mole of an electrolyte in a solution, the power of conducting a solution is termed molar conductivity. asked Jul 24, 2018 in Chemistry by. e. Molar conductivity is defined as the conductivity of an electrolytic solution divided by the molar concentration of the electrolyte mkc On increasing the temperature. The limiting molar conductivity of the solution is . The ionic compounds behave as good conductors in. The molar conductivity of strong electrolytes is expected to follow the Kohlrausch law (Equation 1). Molar conductivity due to ions furnished by one mole of electrolyte in solution. (a, c) NCERT Exemplar (Objective) Based MCQs Electrochemistry Chemistry Practice questions, MCQs, Past. 9 and λ Cl– = 76. The ionic conductivity can be determined by various methods. 8. The conductance of a solution depends on 1) the concentration of the ions it contains, 2) on the number of charges carried by each ion, and 3) on the mobilities of these ions. of ions present in solution. Water was bidistilled, deionized and degassed. Thus mathematically, the limiting molar conductivity of [ A_{x}B_{y}] can. Measure the conductivity of the solution. 2 g of solid calcium carbonate ((ce{CaCO3}) into a small, clean beaker and test the conductivity. . 1) M X ( a q) = M ( a q) + + X ( a q) –. This type of conductance is known as ionic conductance. Solution: Question 21. 0 M sodium chloride to the DI water and stir. The conductance of a given solution having one mole electrolyte is referred as molar conductivity. This type of conductance is known as ionic conductance. Answer: Molar conductivity of an ionic solution is defined as the conductivity of an electrolytic solution divided by the concentration of the electrolytic solution. The conductivity of an electrolyte solution is related to the strength of the electrolyte. (iii) concentration of electrolytes in solution. Example 1: The resistance of a conductivity cell containing 0. Additionally, liquid electrolytes typically exhibit a slope of ∼1. e. Table 1. The equation Λ m = ( k x1000)/M can be used to get units of molar conductance. Ionic conductivity of Ga-doped LLZO prepared using Couette–Taylor reactor for all-solid lithium batteries. Molar conductivity of ionic solution depends on _____. The conductivity maximum for IL + water is at a level of ca. View Solution. 1 M C H 3 C O O H solution is 7. Note: The general definition of molar conductivity is presented as the conducting power of all the ions which are produced by dissolving one mole of an electrolyte in the solution. The molar conductivity of cation and anion of salt B A are 1 8 0 and 2 2 0. where A, B A, B - Debye–Hückel–Onsager coefficients;6. 4945 Å) and the molar conductivity at infinite dilution (50. In general, smaller ions have greater conductivity than larger ions. Nature of electrolyte – Strong electrolytes have high conductance whereas the weak electrolytes have low conductance. where λ + and λ-are the ionic conductivities of the positive and negative ions, respectively, and ν + and ν-are their stoichiometric coefficients in the salt molecular formula. For aqueous solutions, this just restates the familiar observation that pure water is a poor electrical conductor. Molar conductance values at infinite dilution of Na+ and Cl- ions are 51. 001M KCl solution at 298K is 1500 ohm in a conductivity cell. Summary 1. 3 M solution of KCI at 298 K is 3. ∴ Λ m = κ CCorrect option is B) λ m=KV With decrease in soncertration, total volume V of the solution containing one mole of electrolyte also increases and decrease in K (conductivity) on dilution of a solution is more than compensated by increase in its volume, hence molar conductivity (λ m) increases. Distance between electrodes. 29 nm −1 mol −1/2 dm 3/2. To study the effect of ε r (c, T) on EC predictions, we have chosen nine 1:1 aqueous electrolyte solutions. Open in App. Single ion conductivities (1: K +, 2: SCN −) of the system potassium thiocyanate in methanol; data and parameters from Ref. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. With the objective to fill this gap and gain further understanding on the fundamental properties of ion conducting materials, we are studying systematically the mechanical. The size of the lattice energy is connected to many other physical properties including solubility,. 2: As potassium chloride (KCl) dissolves in water, the ions are hydrated. We can then use the molecular weight of sodium chloride, 58. l A R Resistance: - specific resistivity l – length of wire A – cross sectional area of wire G Conductance: Conductivity: Molar conductivity: 1 R 1 Ω-1 = S (Siemens) unit: m-1 Ω-1 = S m-1 Λm unit: if c. 4. Variation of Conductivity and Molar Conductivity with change in concentration 5. κ = l RA κ = l R A. Ionic Electrolytes. \Lambda_\infty = \Lambda_\infty^+ + \Lambda_\infty^- Λ∞ = Λ∞+ +Λ∞−. It is denoted by µ. nature of solvent and nature of solute. mol -1 (Siemens X meter square per mol). . Suppose the soluble ionic compound. 10. 1 is known as the Debye-Hückel Limiting Law. (ii) Copper will dissolve at anode. (ii) distance between electrodes. 1 mho/m = 1 rom = 1 S/m. 1 S cm2mol-1 and 7°(C1-) = 76. You need to add the limiting ionic conductivities for HX+ H X + and OHX− O H X − together to get the limiting ionic conductivity for all the ions in solution ( Λ0 Λ 0, which will replace Λ0m Λ m 0 in your equation). molar conductivity is a valuable quantity to construct linear relationship with the transport properties. (iii) Conductivity does not depend upon solvation of ions present in solution. 001 mol/L;. 8. (ii) distance between electrodes. Step by step video, text & image solution for Molar conductivity of ionic solution depends on_____. The molar conductivity of solution is equal to the sum of the ionic contributions. (ii) distance between electrodes. Concentration of electrolytes in solution. 2. (a, c) NCERT Exemplar (Objective) Based MCQs Electrochemistry Chemistry Practice questions, MCQs, Past. The probes used in this experiment measure conductivity in either mS/cm or S/cm. Figure 1 shows the temperature and concentration dependence of the molar conductivity of potassium iodide in ethanol. 6 g of a solute is dissolved in 0. The peak fractions from the HI-100 mM phosphate peak (which has conductivity equivalent to ~ 200 mM KCl) are diluted 1:4 in HI-0 to reduce the ionic strength to the equivalent of ~ 50 mM. However, the "molar ionic conductivity" of H+ and OH- is greater than all other ions, so in a solution containing many species of ion, the H+ and OH- ions would usually have the most effect on. ” The equation is reliable for c < 0. Early studies by Kahlenberg and Lincoln [], and extended by Lincoln [], demonstrated that the electrical conduction of salts increased with the increasing. As was expected, the ionic conductivity of all salts under consideration exhibits a continuous increase with temperature, this. Nov 19,2023 - Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). It increases with increase in size of solvated ion. There is less resistance as they move through the solution. Hard Solution Verified by Toppr Correct options are A) and C) Λ m(Scm 2mol −1)=K For weak electrolytes (i. Pour 100 (±1) cm of 1 (±0. 5. Molar Conductivity; At temperature (mathrm{T}) and pressure (mathrm{p}), the molar conductivity of given salt solution Λ depends on the. The ionic strength of a solution is a measure of the concentration of ions in that solution. The molar conductivity of the solution formed by them will be. It is the reciprocal of resistivity (p). The conductance of a solution containing one mole of solute is measured as molar conductivity. 85 S cm 2 mol −1 (11) . Temperature; Mobility of ions; Viscosity of electrolyteIt is also very different from ionic solutions, such as aqueous sodium chloride for example, which exist as liquids at room temperature only due to the presence of a solvent. 9 and λ Cl– = 76. 1 mol L−1. Correct options are A) , B) , C) and D) The conductance of a solution depends upon its dilution, no. The capacity effect has been evaluated and found to be below the reproducibility of the measured value. For aqueous solutions at 25 °C A = 0. Example Definitions Formulaes. View solution > View more. (iv) surface area of electrodes. 2 S. As the concentration decreases, molar conductance increases. The protein sample (up to 5–7 mg protein per mL of column) is loaded onto a Mono Q anion exchange column (GE Biosciences) equilibrated in HI-50 m M KCl. Verified by Experts. S. (iii) concentration of electrolytes in solution. 1) M X ( a q) = M ( a q) + + X ( a q) –. (i) the nature of electrolyte added. 2. Distance between electrodes c. Water and other polar molecules are characterized by a slightly positive region and a slightly negative region and are therefore attracted to ions, as shown in Figure (PageIndex{2}). The conductance of electricity by ions present in the solutions is called electrolytic or ionic conductance. The total electrolyte. 5) Medium View solutionThe theory considers the vicinity of each ion as an atmosphere-like cloud of charges of opposite sign that cancels out the charge of the central ion (Figure 25. If triple ions form in a solution, one can expect an increase in molar conductivity; in turn, higher aggregate formation causes a reduction in conductivity (Fig. Updated on: 21/07/2023. Concentration of electrolytes in solution d. The precise and accurate thermophysical properties determination of ionic liquid (IL)-solvent binary system is needed for understanding the molecular interactions occurring between these components. Molar conductivity of ionic solution depends on (i) Temperature Molar conductivity of electrolyte solution increases with increase in temperature . Molar conductivity of. 4, Fig. Temperature and concentration of electrolytes determine the molar conductivity of an ionic solution Therefore, the molar conductivity of the KCl solution is 76. (b) What is the difference between primary battery and secondary battery? Give one example of each type. Temperature. In more dilute solutions, the actual. (i) temperature. 5M Solution of an Electrolyte is Found to be 138. 2 shows the Walden plots of ionic liquid [C4py][DCA] and other ILs. Mark the correct choice as. ionic conductivity depends on the ability of charged ions to move through the medium. Dependence of the molar conductivity of strong, intermediate and weak electrolytes on their concentration. For example, sodium chloride melts at 801 °C and boils at 1413 °C. Molar conductivity, which can be determined by a solution’s ionic strength or salt concentration, is the conductance of a solution containing one mole of electrolyte. We can use the rearranged molarity equation to calculate the moles of NaCl needed for the specified concentration and volume: mol NaCl = [ NaCl] × L of solution = 0. Recommended Questions. concentration of electrolytes in solution. The conductivity attributable to a given ionic species is approximately proportional to its concentration. In order to determine concentration from conductivity, the ionic composition of the solution must be known. The specific conductance κ, the molar conductance Λ m and molar concentration C are related by the expression, Λ m = C 1 0 0 0 κ Λ m = 0. 2. Kohlrausch Law. The molar conductivity κM κ M is the conductivity divided by the molar concentration of electrolyte ( C C ). 16. Molar conductivity of ionic solution depends on _____. the velocity of H + ions is more than that of N a + ions. Molar conductivity is defined as the conductivity of an electrolytic solution divided by the molar concentration of the electrolyte mkc On increasing the temperature the mobility of ions increases Hence molar conductivity increases by increasing temperature Also molar conductivity and concentration of electrolyte is inversely proportional to. 2. Molar conductivity of ionic solution depends on: This question has multiple correct options. 01) g. (iv) surface area of electrodes. It is used to determine the efficiency of the electrolyte in the conducting electricity in solution. nature of solvent and nature of solute. For the given cell, Mg|Mg 2+ || Cu2+ |Cu (i) Mg is cathode (ii) Cu. Q1. . It has been almost one century since Onsager developed the limiting law of equivalent conductivity of electrolyte solutions. A more general definition is possible for an arbitrary geometry or sample composition. e. For a salt solution prepared using a 1:1 salt , the molar conductivity can be expressed as the sum of ionic conductivities , (lambda_{+}) and (lambda_{-}). The molar conductivity of strong electrolytes is expected to follow the Kohlrausch law (Equation 1). To calculate the conductivity of a solution you simply multiply the concentration of each ion in solution by its molar conductivity and charge then add these values for all ions in solution. $kappa $ = specific conductivity c = concentration in mole per litre. 20 = 124 cm² mol⁻¹. studied concentrated aqueous solutions of KCl, MgCl 2, and its mixtures while Lee and Rasaiah calculated ionic conductances of alkali metal ions in water at 25 °C with the help of MD simulations. Research into the electrical conductivity (σ) of non-aqueous liquids began largely around the turn of the 20th century, following on from studies of ionic conduction in aqueous solutions. The electrolytic conductivity of both sets of these solutions as a function of molality was determined. Fig. 80g Volume. Was this answer helpful? This decrease is translated as a decrease in molar conductivity. The molar conductivity of OH-is 3-5 times the conductivity of other small anions. Molar conductivity of ionic solution depends on a. The conductivity of an electrolyte solution depends on concentration of the ionic species and behaves differently for strong and weak electrolytes. A. Electrical conduction is a property of ionic solutions and the conductance of such electrolytic solutions depends on the concentration of the ions and also the nature of the ions (charges and mobilities). Figure : The conductivity of electrolyte solutions: (a) 0. (ii) size of the ion produced and their solvation. (ii) Copper will dissolve at anode. To illustrate the relation between transference numbers and conductivity, the transport number of potassium in dilute potassium chloride solution is used to find the limiting ionic conductivity. Solution: The molar conductivity can be calculated by for mula, c 7. Dispose of this solution in the sink and rinse the beaker. Use this information to estimate the molar solubility of AgCl. 15 K at 5 K intervals. In 1880 the German physicist George Kohlrausch introduced the concept of molar conductivity which is used to compare conductance of different solutions. At infinite dilution, all ions are completely dissociated. Ionic solids typically melt at high temperatures and boil at even higher temperatures. (iv) surface area of electrodes. Thus, Molar conductivity (Λ) = 100 × Conductivity. Specific conductivity passes through a maximum with an increase in the concentration of electrolyte in aqueous solutions (Figure 10 a) and in non-aqueous solutions of ionic liquids (Figure 12 a). Fluid Phase Equilib. (M = Molar concentration or the number of moles of solute per litre solution) = k ×1000M ( ∵ The unit of M is expressed in molarity i. 16. A. The ratio of specific conductivity to the observed conductance does not depend upon the concentration of the solution taken in the conductivity cell. Conductivity κ , is equal to _____. One of the main characteristics of a solution with dissolved. Measure the conductivity of the solution. Elementary science introduces this phenomenon as a property of liquid electrolyte solutions. The measurements were done in five replicate runs. Calcium sulfate is slightly soluble; at equilibrium, most of the calcium and sulfate exists in the solid form of calcium sulfate. surface area of electrodes. The ionic conductivity enhanced to 1. Molar ionic conductivites of a bivalent electrolyte are 57 and 73. Molar conductivity of ionic. I. The Debye-H"uckel-Onsager theory successfully predicts the conductivity at very low ionic concentrations of up to a few millimolars, but there is no well-established theory. But the decrease in specific conductivity on dilution is more than compensated by theThe conductivity of electrolytic (ionic) solutions depends on: (i) the nature of the electrolyte added (ii) size of the ions produced and their solvation. Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. 1 S/m = s 3 * A 2 / kg * m 3 where s is second, A is ampere, kg is kilogram, m is meter. 14. 9 S cm 2 mol −1. Molar conductivity of ionic solution depends on. The latter. Its size depends on the. 0 × 1 0 − 4 s m 2 m o l − 1, (Ag: 108 and CI: 35. Conductivity of these type of solutions. 10. Hence, conductivity of electrolytic solutions depend upon. Similar Questions. 2 13. (v) temperature (it increases with the increase of temperature). False It depends on the experimental parameters. This chapter does not replace the official Water Conductivity á645ñ procedure, which is used to ensure the ionic purity of compendial waters such as Water for Injectio n, Purified Wate r, Pure Stea m condensate, and Sterile Water for Injectio nreached,the conductivity is strongly dependent on the number of free ions in the electrolytes. Molar conductivity of ionic solution depends on: This question has multiple correct options. Solutions prepared from potassium chloride in 30 %This will make the solution conductive in its own manner. Concentration of electrolytes in solution d. The conductance of electricity by ions present in solutions is called electrolytic conductance or ionic conductance. Molar conductivity of ionic solution depends on a. 92–98 mS/cm at T = 298 K, while in the case of non-aqueous MLs the maximum is at ca. * Ionic conductivity depends on : (i) the nature of the electrolyte added (ii) size of the ions produced and their solvation (iii) the nature of the solvent and its viscosity (iv. where l and A describe the geometry of the cell. C. For an ideal measurement cell and electrolyte it is defined as. Table 7 presents the ions studied in this study and their crystallographic ionic radii and ionic conductivity at infinite dilution. Surface area of electrodes The correct choice among the given is - 1. b. 5 A V –1 dm 2 mol –1) which yield one. where α is a constant between zero and unity, V m is the molar volumes, ρ is the density, and M is the molar mass. Conductivity or specific conductance k (kappa): It is the conductance of solution kept between two electrodes with 1 m 2 area of cross section and distance of 1 m. Diffusion coefficients and molar conductivities in aqueous solutions of 1-ethyl-3-methylimidazolium-based ionic liquids. Because a given cell constant can be used only over a limited range, two, possibly three, cell constants are required to cover the. 10 W · m 2 · mole −1 · K −1 · 10 −6 (the mean value is 19. 05 M NaCl (c) 0. Clarification: Conductance is dependent on the concentration of the electrolytic solution. MX(aq) = M+(aq) +X–(aq) (8. 00x10-2 M CaCl2 solution. (a, c) are both correct options. 27 -1 cm2 mol-1. The conductivity of electrolytic (ionic) solutions depends on: i) the nature of the electrolyte added ii) size of the ions produced and their solvation iii) the nature of the solvent and its viscosity iv) concentration of the. κ = l RA κ = l R A. 1,2 The electrochemically active ion in alkaline electrolytes is the hydroxide ion. Open in App. Molar conductivity is the conductance of the total volume of the solution which contains one mole of solute. It is affected by the nature of the ions, and by viscosity of the water. Factors on which conductivity of electrolytic solution depends. The conductivity of 0. For example, with increases in dilution, the number of ions present in the solution increases and the conductance of the solution increases. Molarity of the Electrolyte is denoted as M. surface area of electrodes. D. Place about 0. Solution For Molar conductivity of ionic solution depends on. Describe the general structure of ionic hydration shells. a. 0 6 1 × 1 0 − 4 S / c m Λ m = 1 0. Molar conductivity of ionic solution depends on (i) Temperature Molar conductivity of electrolyte solution increases with increase in temperature . solutions at a low concentration, I < 0. Molar conductivity is the property of conductance of a solution containing an electrolyte mole or is a function of the ionic resistance of a solution or concentration of salt. View solution > Molar conductivity of ionic solution depends on: This question has multiple correct options. Medium. This feature is associated with the mass transition caused by the viscosity and conductivity of the solvent, which depends on temperature. The limiting molar conductivities of H C I, C H 3 C O O N a and N a C I are respectively 4 2 5, 9 0 and 1 2 5 m h o c m 2 m o l − 1 at 2 5 o C. (iv) The conductivity of the solution increases with temperature. 00 (±0. Measurement of the Conductivity of Ionic Solutions. For example, acetic acid has a higher molar conductivity in dilute aqueous acetic acid than in concentrated. The conductivity of electrolytic (ionic) solutions depends on: (i) the nature of the electrolyte added. - Chemistry ExemplarMolar conductivity of ionic solution depends on - Doubtnut is No. May 7, 2020 at 15:37. The only requirement is. is the physical property that has the biggest impact on the performance of a given material [41]. ∙ Nature of the electrolyte added. • The magnitude of the conductivity exhibited by the ionic solution depends on a number of factors. directly into ionic liquid solutions andthe reading has been recorded. From left to right are Mg2+, Ca2+, Sr 2+, and Ba2. (iv) surface. Elementary science introduces this phenomenon as a property of liquid electrolyte solutions. 63 10 Sm molMolar conductivity is the conductivity due to ions furnished by one mole of electrolyte in solution. Click here👆to get an answer to your question ️ Electrolytic conductivity of 0. In dilute solutions, the conductivity of the electrolyte solution is the sum of the conductivities of the ions in the solution, which can be expressed by the following equation: 20. Variation of Molar Conductivity with Concentration. The total electrolyte concentration in solution will affect important properties such as the dissociation constant or the solubility of different salts. Measuring the conductivity of the solution thus is – in principle – a simple means to determine ionic concentrations if molar conductivities are known, but there are a couple of problems. The conductivity of ionic solutions is arguably their most important trait, being widely used in electrochemical, biochemical, and environmental applications. B. This type of conductance is known as ionic conductance. nature of solvent and nature of solute. A conductivity cell was calibrated. 9C. Calculate its molar conductivity ( S cm^2 mol ^-1 ). 42 W · m2 · mole−1 · K−1 · 10. The molar conductivity of OH-is 3-5 times the conductivity of other small anions. Molar conductivity increases with a decrease in the concentration of the solution. Add 5 mL distilled water to the calcium carbonate; test the conductivity of. A. (iii) Oxygen will be released at anode. “conductivity”) of fluid solutions, including pure fluids. Understanding the electric conductance of concentrated electrolytes has posed a great theoretical challenge for over a century. In solutions, where ionic complexation or associaltion are important, two different tramsport/tramsference numbers can be defined. The electrical conductivity of a solution of electrolytes, κ, is the sum of all ions in the solution. Nature of solvent and its viscosity. 15 K. How do conductivity and molar conductivity vary with concentration?. molar conductivity decreases. So the more the concentration is, the more the conductivity will be. It is the conducting power of the ions that is formed by. What effect does concentration have on the molar conductivity of a strong electrolyte? Medium. Upon dilution, the degree of dissociation ( fraction of the total number of moles which dissociate into ions) increases. 1molL −1KCl solution is 1. 12 × 10-4 Sm2mol-1 and 73. Surface area of electrodes. (c, d) 4. It is a measure of the cohesive forces that bind ionic solids. It is related to the conductivity of the solution. Determining molar conductivity of Naci Stock Solution Stock NaCl solution Supporting Calculation Mass of NaCI none required 8. 1 ). 31 S-cm 2 /mol for Na + and Cl-,. Ionic conductivity of solution depends on following parameter : (A) nature of electrolyte. A. In simple words, molar conductivity can also be defined as the conductive power of all ions formed by dissolving an electrolyte mole in a. Λ = κ / C or Λ = κV. S = κ ·. Ionic conductivity and transference number. μ =−μ exp( )Cz Ibc ii0i (3) I = ∑mz 1 2 ii 2 (4) where μ i0 is the mobility of ion i at infinite dilution; I is the ionic strength; m i is the molar concentration of ion i; z is the ionic valence. Semiconductors: band structure determines the number of charge carriers. Solution For [Solved] Molar conductivity of ionic solution depends on. 2012) for calculating conductivity of a mixed electrolyte solution from its chemical composition: (3) where is the ionic molar conductivity and mis the speciated molality of the ith ion. (iv) the surface area of electrodes. 1 M C H 3 C O O H solution is 7. (a, b) 2. The water solubility of molecular compounds is variable and depends primarily on the type of. The electrolytic or ionic conductivity depends on the following factors:. 66 cm² mol⁻¹. For the case of electrolyte solutions, their ionic nature and dipolar polarization, make them have essential roles in microwave-assisted chemical reactions, however, the mechanism of microwave. Nature of electrolyte: Ionic mobility also depends upon the nature of the electrolyte. Which of the statements about solutions of electrolytes is not correct? (i) The conductivity of the solution depends upon the size of ions. 08 and 76. The set up for the measurement of the resistance is shown in Fig. However, I am looking for values at 1 M, and I'm having a hard time finding that information. 8 Answers 5. To clarify the regularity of the appearance of the maximum on the κ− c curves, let us consider how the distance between ions in solutions changes. As C C decreases, so does C−−√ C, and thus 1 C√ 1 C increases, while A A remains constant. Pure CMC shows a low ionic conductivity (σ = 7. Hard. Ionic conductivity is electrical conductivity due to the motion of ionic charge.